I was standing on my balcony facing East, looking at the big dipper, when I noticed at first what I thought was an aircraft on approach to YYZ come across the bottom part of the big dipper from my FOV in a Southernly direction at high altitude, traveling at what you may expect to see an airliner moving at. The light became brighter during it's path, and I figured it was lowering it's altitude while I watched. The light then went much dimmer and quickly went out of sight as if it the light just went out.

There were no clouds, and I could see all the other star formations around where it vanished. I thought that was pretty weird, then noticed a second, slightly dimmer light also at high altitude approach the same area from the East, and also vanished in pretty much the same area of sky. As I said, there were no clouds, and my view was unobstructed.

One aircraft had taken off from YYZ in a North then Westernly direction shortly before these events, which is not unusual.